Liquefied gas container

ABSTRACT

951,875. Storing liquefied gases. SUPERIOR AIR PRODUCTS CO. Sept.17, 1962 [Oct. 9, 1961], No. 35293/63. Heading F4P. A container for the storage of liquefied gas comprises a storage chamber 10 having a vacuum jacket 13 thereabout, a first tube 27 communicating at one end thereof with the chamber 10 for the introduction and removal of the liquefied gas, a second tube 29 arranged in spaced relation to the tube 27 through a major portion of the length of the tube 27 which with the tube 29 defines an elongated space 30 communicating at one end thereof with the chamber 10, and a pressure relief valve 32 communicating with the space 30 and arranged to open to the atmosphere, the space 30 being closed except at the said one end thereof and at the pressure relief valve. The chamber 10 is defined by a wall 11 which is surrounded by a spaced wall 12, the space between the walls 11 and 12 forming the jacket 13. The jacket 13 may be insulated by other means, e.g. multiple reflector shields. Another wall 14 surrounds the wall 12, the space 15 between the walls 12 and 14 being filled by another liquefied gas which acts as a heat shield. If the stored gas is helium, hydrogen or neon, the other gas may be nitrogen. An outer wall 16 surrounds the wall 14, the space 17 between the walls 14 and 16 being evacuated; the space 17 may be insulated by other means also. The walls 11, 12, 14 and 16 and the tubes 27 and 29 are preferably made of stainless steel or Monel metal. A tube 34 is spaced from and surrounds the tube 29 and is preferably made of copper or a copper alloy having high heat conductivity, the space 35 between the tubes 29 and 34 being sealed by a ferrule 36 made of the same material. A tube 37 is spaced from and surrounds the tube 34 and tube 39 is spaced from and surrounds the tube 37, the tubes 37 and 39 being made of stainless steel or Monel metal; alternatively the tube 39 may be made of copper. A ferrule 42 seals off the space 40 between the tubes 37 and 39 and extends almost to the tube 29 to which it is joined by a bellows member 45. A filling tube 46 extends through the space 38 into the gas space 15, the gas in the latter being vented to atmosphere through a tube 47. A serrated ferrule 48 made of copper or copper alloy extends between the tubes 27 and 29 in the area of the ferrule 36. The above construction ensures that heat travelling down tubes 27 and 29 will be diverted away from the gas in chamber 10 to that in space 15. The serrated ferrule 48 may be replaced by a ferrule having axial holes passing therethrough.

July 9, 1963 L. E. PUTMAN LIQUEFIED GAS CONTAINER Filed Oct. 9, 1961 2 Sheets-Sheet 1 July 9, 1 963 1.. E. PUTMAN LIQUEFIED GAS CONTAINER 2 Sheets-Sheet 2 Filed 001.. 9, 1961 FIG. 4

United States 3,097,084 Patented July 9, 1963 Ware Filed Oct. 9, 1961, Ser- No. 143,722 6 Claims. (Cl. 62-45) The present invention relates to storage containers {or liquefied gases and more particularly to vacuum jacketed containers for the storage and transport of liquefied gases, such as helium, hydrogen and neon, which must be maintained at a very low temperature.

In the use of vacuum jacketed storage containers for liquefied gases, such as helium, hydrogen and neon, a problem has been encountered due to the occasional iormation of a blockage in the access opening or neck. Such a block may result from the formation in the access opening or neck of solidified air or ice or a mixture of solidified air and ice. Air or water may enter the neck during transfer of liquid or during storage or transport, especially in aircraft service. And the air, water or both may freeze from exposure to the low temperature of the stored liquid. Such a blockage in the neck creates a hazardous condition, since flow of heat into the liquid storage space tends to vaporize the liquefied gas. If

the container neck is completely blocked, as sometimes occurs, the buildup in pressure within the storage space .can cause the container to burst.

, It has been a principal object of the invention to provide a novel and improved storage container for liquefied gases in which relief is aiiorded against a pressure buildup due to a blockageof the container neck. The term 'nec is intended to signify not only the usual dorm of container. access tube shaped generally as a neck but also various other forms of constricted access openings. Another object of the invention has been the provision of such a storage container in which the heat conduction paths to the storage space are minimized, thus aifording improved container efficiency.

Other and further objects, features and advantages of the invention will appear more tully irom the iollowin-g description of the invention taken in connection with the appended drawings, in which:

FIG. 1, is a longitudinal sectional view of the body and a portion of the neck of a container embodying the invention;

FIG. 2 is a longituidnal sectional view showing a major portion of the neck of the container of FIG. 1 but "to a larger scale than in FIG. 1;

FIG. 3 is a top plan view of a [ferrule her use in the container neck of FIGS. 1 and 2; and

FIG. 4 is a longitudinal sectional view taken along the line 4-4 of FIG. 3.

Referring'now to the drawings, the liquefied gas is stored in a-chamber I defined by an inner container wall 11 which is closed except at the upper end thereof, as will be described below. An intermediate container 'wall 12 surrounds and is spaced from the wall 11. The

walls 11 and '12 define a space 13 which is evacuated so as to provide a relatively high vacuum which minimizes transfer of heat from wall 12 to wall 11. The space 13 may also be insulated by other means such as multiple reflector shields or mass-vacuum insulation, as is well known in the art.

Another intermediate container wall 14 surrounds and is spaced irom the wall 12. The walls 12 and 14 define a space 15 which is filled with a liquefied gas which acts as a heat shield to absorb heat which travels from the outside toward the inside of the container. It the stored liquefied gas in chamber 10 is helium, hydrogen or neon, the liquefied gas in the space 15 may be nitrogen. The liquefied nitrogen (or other liquefied gas) in space 15 minimizes the transfer of heat by radiation from wall 12 to wall 11 since the temperature of wall '12 is that of liquid nitrogen and liquid nitrogen temperature is closer to the temperature of the liquefied gas in chamber 10 than room temperature. For convenience, the liquefied gas in chamber 10 will be refer-red to as helium.

The outer container wall 16 surrounds and is spaced from the wall 14. The walls 14 and 16 define a space 17 which is evacuated so as to provide a relatively high vacuum which minimizes transfer of heat from wall 16 to wall 14. Space 17 may be insulated to prevent heat transfer by radiation by other means, such as multiple reflection barriers or mass-vacuum insulation.

The walls 11, 12, 14 and 16 may be generally spherical or of any other convenient shape, and may be made of any suitable materials as generally used in low temperature vacuum jacketed storage containers. Usually these walls will be made of metal to provide substantial strength. Stainless steel or Monel metal may be used toadvantage because of their relatively low heat conductivity.

At their upper ends the walls 11, 12, 14 and 16 each terminate in a respective one of throats 18, 19, 20 and 21. The upper ends of the throats 18-21 are formed by open-ended cylindrical sections 22, 23, 24 and 25, respectively. The cylindrical sections 22-25 are concentric and are vertically spaced from each other.

The container neck is generally designated by the reference numeral 26 and is made up of a series of concentric hollow tubes. The innermost tube 27 is a long thin-walled tube made of a relatively poor heat-conductive material, such as stainless steel or Monel metal, and serves as the access passage for introducing or removing liquefied helium to or from chamber 10. For this purpose, the lower end of tube 27 extends into chamber 10. The upper end of tube 27, designated 28, is shown open, but a suitable removable stopper, plug or fitting will be provided to close off the chamber 10 from access to ambient atmosphere.

A thinwalled tube 29, also made of a relatively poor heat conductive material, such as stainless steel or Monel metal, surrounds the tube 27 except for the upper and lower ends thereof and defines therewith an annular space 30. The tube 29 is rigidly attached, as by soldering, adjacent the lower end thereof to cylindrical section 22, the attachment forming a gastight seal. The

space 30 communicates at the bottom with chamber 10.

The space 30 at the upper end thereof communicates through the interior of a hollow fitting 31 and a relief device 32 with the atmosphere.

The fitting 31 has a hollow cylindrical body the lower end of which is rigidly affixed, as by soldering, to the upper end of tube 29, the joint therebetween being gastight. The upper end of fitting 31 is closed by an annular ring 33 which provides a gas-tight connection between fitting 3'1 and the outer surface of tube 27. Ring 33 Pre vents communication between the upper end of space 39 and the atmosphere except through relief device 32.

A tube 34 surrounds the tube 29 and forms therewith an annular space 35 which communicates with the space 13. The tube 34 should be made of a material of high heat conductivity, such as copper or a copper alloy. The lower end of tube 34 is rigidly attached to cylindrical section 23 by gas-tight means, such as soldering, and effectively forms a continuation of wall 12. A gas-tight seal is provided between tubes 29 and 34 at an intermediate point on tube 29 and at the top of tube 34 by a ferrule 36. The ferrule 36 closes oif the top end of space 35. The ferrule 36 should also be made of a high heat conductivity material, such as copper or a copper alloy.

A tube 37 surrounds the tube 34 and for-ms therewith and with tube 29 an annular space 38 communicating at its lower end with the space 15. The tube 37 is preferably made from a low heat conductivity material, such as stainless steel or Monel metal. The lower end of tube 37 is rigidly attached to cylindrical section 24 by a gastight connection, such as soldering, and forms an extension of wall 1-4.

A tube 39 surrounds the tube 37 and forms therewith an annular space 44 communicating at its lower end with space 17. Tube 39 forms the outer wall of container neck 26 and the lower end thereof is rigidly attached, as by soldering, to cylindrical section 25 by a gas-tight connection. The tube 39 forms an extension of wall 16 and may be made of any suitable material, such as copper, stainless steel or Monel metal.

A ferrule 42 has an annular flange 43 extending between walls 37 and 39 to seal off the upper end of space 4t}. The ferrule 42 extends inwardly almost to tube 29, being separated therefrom by an annular space 44 which provides communication between space 38 and the interior of a bellows member 45, which surrounds a length of tube 29 above ferrule 42. The lower end of bellows 45 is afiixed to the top of ferrule 42 by a gas-tight connection, while the upper end of bellows 45 is affixed to the outer wall of tube 29, likewise by a gas-tight connection. These connections may be soldered.

The bellows 45 provides the only mechanical connection between inner tubes 27, 29 and 34 and walls 11 and 12 on the one hand and outer tubes 37 and 39 and outer walls 14 and 16 on the other hand. Contraction or expansion of bellows 45 allows the walls 11 and 12 to move freely to compensate for contraction and expansion when the container is cooled down for use or warmed up to room temperature.

Ferrule 42 is provided with a hole which accommodates a tube 46. The upper end of tube 46 extends outwardly into the atmosphere, while the lower end thereof extends into the space 15 adjacent the bottom of the container. Tube '46 is used to fill the spaces 15 and 38 with liquid nitrogen.

A short tube 47 mounted in another hole in ferrule 42 provides communication between the upper end of space 38 and the atmosphere and serves as a vent to permit nitrogen gas vaporized as a result of heat flow to the spaces 15 and 38 to pass off into the atmosphere.

A serrated ferrule 48, which should be made of a highly heat conductive material, such as copper or a copper alloy, is firmly attached, as by soldering, to the outer surface of tube 27 and is in close thermal contact with the inner surface of tube 29 in the area where ferrule 36 seals walls 29 and 34 together. As shown in FIGS. 3 and 4, ferrule 48 is in the [form of a hollow cylinder having serrations formed by arcuate recesses 49, 50, 51 and 52 evenly spaced about the outer surface thereof and leaving lands 53, 54, 55 and 56 of the cylindrical periphery in surface contact with the inner surface of tube 29.

It will be recalled that the space 38 is filled with liquid nitrogen. Hence the tube 34, which forms the inner wall of space 38 and which is a good heat conductor, will be essentially at liquid nitrogen temperature. Similarly, the ferrules 36 and 48 will be essentially at liquid nitrogen temperature. That portion of tube 27 which is contacted by ferrule 48 will likewise be essentially at liquid nitrogen temperature. Heat traveling down tubes 27 and 2@ from room temperature will be diverted through ferrules 48 and 36 into the liquid nitrogen in space 38. Hence the heat reaching chamber 19 by conduction through tubes 27 and 29 will be only that heat available at liquid nitrogen temperature.

Should the tube 27 be plugged, as by the formation therein of ice or solidified air, and should heat reaching the liquid helium in chamber '10 cause the helium pressure to build up appreciably, helium gas will fiow upwardly through the lower part of annular space 33, through serrations 49-52 of ferrule 48, and through the upper part of annular space 38 and fitting 31 to relief device 32. The relief device 32 may be any suitable form of pressure relief valve which will open to vent the space 38 to the atmosphere when the helium gas pressure exceeds a predetermined safe value. While the serrated ferrule construction has been found preferable, a ferrule with a cylindrical outer surface and one or more axial holes or other fluid passages could be used.

As shown, the pressure relife device 32 comprises a hollow body 57 having a threaded nipple 58 at one end in threaded engagement with a threaded hole in a bushing 59 which closes the open end of fitting 31. An annular washer at} is seated in an annular groove in the housing 57. An annular seat seal 61 is mounted in an annular shoulder at the right of washer as. A hollow valve stem 62 has an annular surface 63 which cooperates with seal 61 to effectively close off the valve. The valve stem 62 is maintained closed by a compression spring 64 which is mounted inside the valve stem so that one end of the spring acts against the end of the valve stem and the other end of the spring acts against a plug 64, which closes the end of a bonnet 65 attached to the housing 57. The end 66 of valve stem 62 is exposed to helium gas pressure entering the valve housing through nipple 58 and washer 60 and acts as a piston tending to force the valve stem 62 to the right against the pressure of spring 64.

When the spring loading is exceeded, valve stem 62 moves to the right and helium passes between surface 63 and seal 61 into an outlet passage 67 communicating directly with the atmosphere. When the excess pressure is relieved, spring 64 forces the valve shut by moving valve stem 62 to the left until surface 63 seals against seat seal 61. Since under normal helium gas pressures in chamber ltl the relief device 32 W11 be closed, the annular space 30 will normally be static in that no gas flow will occur therein. Hence there is no danger that a solidified air or ice plug will foam in the annular space 30 which would prevent the pressure relief action when the pressure of vaporized liquid helium builds up beyond a desirable safe level.

While the invention has been described in connection with a specific embodiment thereof and in a specific use, various modifications thereof will occur to those skilled in the art without departing from the spirit and scope of the invention as set forth in the appended claims.

What is claimed is:

1. In a vacuum jacketed container for the storage of a liquefied gas at a low temperature substantially below ambient temperature, the combination comprising a storage chamber for said liquefied gas, a jacket surrounding said chamber and containing a liquefied gas at a temperature substantially below ambient temperature and serving as a barrier to the flow of ambient heat to said chamber, a first hollow elongated tube communicating at one end thereof with said chamber for the introduction and removal of liquefied gas to and from said chamber, a second hollow elongated tube concentric with and surrounding said first tube through a major portion of the length of said first tube, said first and second tubes defining an elongated annular space communicating with said chamber at one end thereof, a pressure relief valve communicating with said annular space adjacent the other end thereof and arranged to open said space to the atmosphere when the pressure of gas in said space exoeeds a predetermined value, said space being closed except for said one end thereof and said pressure relief valve, and heat conductive means arranged in thermal contact with said liquefied gas in said jacket and with said tubes thereby to conduct ambient heat traveling through said tubes to the liquefied gas in said jacket.

2. In a vacuum jacketed container for the storage of a liquefied gas at a low temperature substantially below ambient temperature, the combination comprising a storage chamber for said liquefied gas, a jacket surrounding said chamber and adapted to contain a liquefied gas at a temperature substantially below ambient temperature and serving as a barrier to the flow of ambient heat to said chamber, a first hollow elongated tube communicating at one end thereof with said chamber for the introduction and removal of liquefied gas to and from said chamber, a second hollow elongated tube concentric with and surrounding said first tube through a major portion of the length of said first tube, said first and second tubes defining an elongated annular space communicating with said chamber at one end thereof, a pressure relief valve communicating with said annular space adjacent the other end thereof and arranged to open said space to the atmosphere when the pressure of gas in said space exceeds a predetermined value, said space being closed except for said one end thereof and said pressure relief valve, a heat conductive member disposed at an intermediate point in said annular space and arranged to be in surface contact with the outer wall of said first tube and the innor wall of said second tube, heat conductive means arranged to be in thermal contact with said member and with said liquefied gas in said jacket thereby to maintain said member substantially at the temperature of the liquefied gas in said jacket, and a fluid passage in said member permitting the flow of vaporized gas through said space from one end of said member to the other end of said member.

3. The combination set forth in claim 2 in which said member is an ferrule.

4. In a vacuum jacketed container for the storage of a liquefied gas at a low temperature substantially below ambient temperature, the combination comprising a first wall defining a liquefied gas storage chamber, a second wall surrounding and spaced from said first wall and defining with said first wall a first space, said first space being evacuated to form a first barrier to the admittance of ambient heat to said storage chamber, a third wall surrounding and spaced from said second wall and forming with said second wall a second space, said second space being adapted to be filled with a liquefied gas having a temperature substantially below ambient temperature and when so filled forming a second barrier to the admittance of ambient heat to said storage chamber, a first elongated hollow tube communicating at one end thereof with said storage chamber for the introduction and removal of liquefied gas to and from said chamber, a second hollow elongated tube concentric with and surrounding said first tube through a major portion of the length of said first tube, said first and second tubes defining a first elongated annular space communicating at one end thereof with said chamber, a pressure relief valve communicating with said first annular space and arranged to open said first annular space to the atmosphere when the pressure of gas in said first annular space exceeds a predetermined value, said first annular space being closed except for said one end thereof and said valve, a third hollow elongated tube concentric with and surrounding a lower portion of said second tube, said second and third tubes defining a second elongated annular space communicating at one end thereof with said first evacuated space, a fourth hollow elongated tube concentric with and surrounding said third tube, said second, third and fourth tubes defining a third elongated annular space communicating at one end thereof with said second liquefied gas containing space, means to introduce liquefied gas into said second liquefied gas containing space and said third annular space, a first highly heat conductive ferrule contacting said second and third tubes and forming a closure for the upper end of said third annular space and a second highly heat conductive ferrule contacting said first and second tubes at substantially the level of said first ferrule whereby said ferrules constitute a path for the ready transfer of heat from said first tube to liquefied gas in said third annular space, said second ferrule having a fiuid passage permitting the fiow of vaporized liquefied gas through said first annular space.

5. In a vacuum jacketed container for the storage of a liquefied gas at a low temperature substantially below ambient temperature, the combination comprising a first wall defining a liquefied gas storage chamber, a second wall surrounding and spaced from said first wall and defining with said first Wall a first space, said first space being evacuated to form a first barrier to the admittance of ambient heat to said storage chamber, a third wall surrounding and spaced from said second wall and forming with said second wall a second space, said second space being adapted to be filled with a liquefied gas having a temperature substantially below ambient temperature and when so filled forming a second barrier to the admittance of ambient heat to said storage chamber, a first elongated hollow tube communicating at one end thereof with said storage chamber for the introduction and removal of liquefied gas to and from said chamber, a second hollow elongated tube concentric with and surrounding said first tube through a major portion of the length of said first tube, said first and second tubes defining a first elongated annular space communicating at one end thereof with said chamber, a pressure relief valve communicating with said first annular space adjacent the other end thereof and arranged to open said first annular space to the atmosphere when the pressure of gas in said first annular space exceeds a predetermined value, said first annular space being closed except for said one end thereof and said valve, a third hollow elongated tube concentric with and surrounding a lower portion of said second tube, said third tube being substantially shorter than said first and second tubes, said second and third tubes defining a second elongated annular space communicating at one end thereof with said first evacuated space, a fourth hollow elongated tube concentric with and surrounding said third tube, said second, third and fourth tubes defining a third elongated annular space communicating at one end thereof with said second liquefied gas containing space, means to introduce liquefied gas into said second liquefied gas containing space and said third annular space, a first highly heat conductive annular ferrule contacting said second and third tubes adjacent the upper end of said third tube and forming a closure for the upper end of said third annular space, a second highly heat conductive annular ferrule contacting said first and second tubes at substantially the level of said first ferrule whereby said ferrules constitute a path for the ready transfer of heat from said first tube to liquefied gas in said third annular space, said second ferrule having a fluid passage permitting the flow of vap d rized liquefied gas through said first annular space from said chamber to said valve, and a jacket surrounding and spaced from said third space and said fourth tube, said jacket, said third wall and said fourth tube defining an outer evacuated space forming an outer barrier to the flow of ambient heat into said chamber.

6. The combination set forth in claim 5 in which the outer wall of said second ferrule is serrated and in which said serrations form said fluid passage.

References ited in the file of this patent UNITED STATES PATENTS 646,459 Place Apr. 3, 1900 707,634 Place Aug. 26, 1902 1,505,095 Heylandt Aug. 19, 1924 2,643,022. Cornell June 23, 1953 2,871,669 Mann et al. Feb. 3, 1959 FOREIGN PATENTS 705,621 France Mar. 16, 1931 

1. IN A VACUUM JACKETED CONTAINER FOR THE STORAGE OF A LIQUEFIED GAS AT A LOW TEMPERATURE SUBSTANTIALLY BELOW AMBIENT TEMPERATUE, THE COMBINATION COMPRISING A STORAGE CHAMBER FOR SAID LIQUEFIED GAS, A JACKET SURROUNDING SAID CHAMBER AND CONTAINING A LIQUEFIED GAS AT A TEMPERATURE SUBSTANTIALLY BELOW AMBIENT TEMPERATURE AND SERVING AS A BARRIER TO THE FLOW OF AMBIENT HEAT TO SAID CHAMBER, A FIRST HALLOW ELONGATED TUBE COMMUNICATING AT ONE END THEREOF WITH SAID CHAMBER FOR THE INTRODUCTION AND REMOVAL OF LIQUEFIED GAS TO AND FROM SAID CHAMBER, A SECOND HOLLOW ELONGATED TUBE CONCENTRIC WITH AND SURROUNDING SAID FIRST TUBE THROUGH A MAJOR PORTION OF THE LENGTH OF SAID FIRST TUBE, SAID FIRST AND SECOND TUBES DEFINING AN ELONGATED ANNULAR SPACE COMMUNICATING WITH SAID CHAMBER AT ONE END THEREOF, A PRESSURE RELIEF VALVE COMMUNICTING WITH SAID ANNULAR SPACE ADJACENT THE OTHER END THEREOF AND ARRANGED TO OPEN SAID SPACE TO THE ATMOSPHERE WHEN THE PRESSURE OF GAS IN SAID SPACE EXCEEDS A PREDETERMINED VALUE, SAID SPACE BEING CLOSED EXCEPT FOR SAID ONE END THEREOF AND SAID PRESSURE RELIEF VALVE, AND HEAT CONDUCTIVE MEANS ARRANGED IN THERMAL CONTACT WITH SAID LIQUEFIED GAS IN SAID JACKET AND WITH SAID TUBES THEREBY TO CONDUCT AMBIENT HEAT TRAVELLING THROUGH SAID TUBES TO THE LIQUEFIED GAS IN SAID JACKET. 